Steerable parachute control system and method

ABSTRACT

An autonomous guided parachute system for cargo drops that divides the requirements of guidance and soft landing into separate parachutes. Said invention includes a high wing-loaded ram air parachute for guidance, a larger round parachute for soft landing, a harness/container system, flight computer, position sensors and actuation system. The system is dropped from an airplane. A predetermined period of drogue fall ensures a stable position prior to deploying the guidance parachute. The flight controller determines a heading to intersect with an area substantially above the desired target and controls the guidance parachute via pneumatic actuators connected to the parachutes steering lines to fly on that heading. At a minimum altitude prior to the system&#39;s impact with the ground the flight computer transitions the system from the fast high performance guidance parachute to a larger landing parachute by releasing the guidance parachute to static line extract and deploy the landing parachute. If the system reaches a position substantially above target area prior to the parachute transition altitude the flight computer controls the system into a spiral dive or other rapid altitude dropping maneuver until the transition altitude is reached. Once transitioned to the landing parachute the system descends for a brief period unguided under the landing parachute until touchdown.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates generally to unmanned parachutes for cargo drops.More particularly, it relates to a control system and method fortargeted landing of cargo using controllable parachutes.

2. Discussion of Related Art

Parachutes have evolved over the years into highly sophisticatedsystems, and often include features that improve the safety,maneuverability, and overall reliability of the parachutes. Initially,parachutes included a round canopy. A skydiver was connected to thecanopy via a harness/container to suspension lines disposed around theperiphery of the canopy. Such parachutes severely lacked control. Theuser was driven about by winds without any mechanism for alteringdirection. Furthermore, such parachutes had a single descent rate basedupon the size of the canopy and the weight of the parachutist.

In the mid-1960's the parasol canopy was invented. Since then,variations of the parasol canopy have replaced round canopies for mostapplications, particularly for aeronautics and the sport industry. Theparasol canopy, also known as a gliding or ram air parachute, is formedof two layers of material—a top skin and a bottom skin. The skins mayhave different shapes but are commonly rectangular or elliptical. Thetwo layers are separated by vertical ribs to form cells. The top andbottom skins are separated at the lower front of the canopy to forminlets. During descent, air enters the cells of the canopy through theinlets. The vertical ribs are shaped to maintain the canopy in the formof an airfoil when filled with air. Suspension[s] lines are attachedalong at least some of the ribs to maintain the orientation of thecanopy relative to the pilot. The canopy of the ram air parachutefunctions as a wing to provide lift and forward motion. Guidelinesoperated by the user allow deformation of the canopy to controldirection and speed. Ram air parachutes have a high degree of lift andmaneuverability.

Despite the increased lift from a ram air parachute, round canopies arestill used for cargo drops. However, as the weight of cargo increases,the size of the canopy must increase to obtain an appropriate descentrate. Reasonable sizes of round parachutes greatly limit the amount ofcargo which can be dropped. Therefore, a need exists for a parachutesystem which can carry additional cargo weight. Additionally, accurateplacement of cargo drops from high altitude with round parachutes isimpossible. Adjustments can be made for prevailing winds at variousaltitudes but the cargo is likely to be drift off course due tovariations. Furthermore, improvements in surface-to-air missilesrequires higher altitude drops in order to protect aircraft. In militaryuse, round parachutes are generally used from an altitude around onethousand (1000) feet to ensure accurate placement. However, new,inexpensive, hand held surface-to-air missiles can put in jeopardyairplanes up to twenty-five thousand (25,000) feet in altitude. Currentmilitary technique is to use a special forces soldier to pilot bothparachute and cargo to the ground from altitudes of twenty-five tothirty-five thousand (25-35,000) feet. This limits cargo to six hundredfifty (650) pounds, as it must be attached to a human. Therefore, a needexists for an autonomous guided parachute system for cargo which canoperate at high altitudes as well as scale to heavier cargo weights.

Autonomous ram air parachutes systems have been developed for cargodrops but suffer from several problems that have prevented them frombeing generally adopted into military techniques. Prior art guidedsystems include a harness/container system, a single parachute, flightcomputer, guidance and navigation control software, a GPS, and electricmotor actuators. The flight computer must calculate a flight path andglide the system from the drop point all the way to the ground target.In order for the flight computer to accomplish this, the parachute usedmust be of low wing loading to ensure docile and slow flight. Suchlightly loaded parachutes fly with free flight forward speeds ofapproximately twenty-five (25) miles per hour or slower. Typical wingloadings are around one (1) pound per square foot of wing area. Suchslow systems present several problems, first they are greatly effectedby winds aloft. At high altitudes winds are quite strong and can beseveral times the forward speed of the wing. This necessitates the needto map out specific winds at each altitude by dropping radio frequencytransmitting sensors units. The collected data must be analyzed andimported to the autonomous systems flight computer to enable a dropposition to be calculated and then a flight path. Another problem is thesystems time in the air with such light wing loaded parachutes is quitelong, increasing their vulnerability and delivery time. Another problemis that higher weight cargo requires proportionally larger wings whichbecome completely impractical far below the maximum weight desired formilitary use. Therefore, a need exists for an improved autonomous guidedparachute system which can provide accurate targeting control from highaltitudes, while flying at higher speeds to reduce or negate windeffects, and be able to scale to the ultimate high weight cargo requiredby militaries.

Typically, static line deployment is used for cargo drops. A line fromthe harness/container is attached to the cargo hold of the deliveryaircraft. The cargo is then pushed out of the hold. The line causes theparachute to be deployed, with or without the use of a drogue. However,air currents around the delivery aircraft can interfere with properdeployment of a gliding parachute using a static line. Also, the cargois not typically falling stable upon immediate exit which can causedifficulties during opening of the gliding parachute. In order toslightly delay opening, existing systems utilize a double-bag deploymentsystem. However, the double-bag system is complicated and expensive toconstruct as well as complicated to pack. Therefore, a need exists foran improved system for delaying the deployment of a gliding parachute.

Additionally prior art systems use electric motor actuators andbatteries. Typically the motors are overly complicated DC servo drivemotors. At high altitudes temperatures are very low. Such systems sufferfrom the requirement for very large, low power density cold weatherbatteries. To meet military demand high altitude systems must operate upto −65 F and existing systems do not function at such temperatures. Assuch there exists a need for lighter simpler actuators and power systemthat are unaffected by extreme temperatures.

SUMMARY OF THE INVENTION

The deficiencies of the prior art are substantially overcome by theguided, multi-stage parachute system of the present invention. Accordingto an aspect of the invention, the parachute system includes twodifferent kinds of parachutes for use during different phases of thecargo drop process. The requirements of guidance and soft landing havebeen separated. A fast, high performance ram air parachute is used toguide the cargo in substantially a straight line from exit point tosubstantially overhead of the target location and then rapidly spiraldive down to lose altitude. The system transitions to a larger unguidedlanding parachute prior to impact. The multi-stage parachute systemutilizes the advantages of different kinds of parachutes to achievegreater control and improved performance. Since the gliding parachute isnot used for landing of the cargo, it can be designed for extremely highspeed and high wing load capabilities. These features allow higherreliability in high altitude drops by limiting the effect of winds andgreatly reduce time aloft. Since the landing parachute is not used tocontrol location, it can be designed for a soft landing of large cargos.Also, it can be deployed at the lowest possible altitudes to minimizeunguided drift.

According to another aspect of the invention, a novel flight controllerprovides control for the parachute system. The flight controllerdetermines the position and altitude of the parachute system. The flightcontroller operates the steering controls of the guidance parachute.Once within a specified radius of overhead the target location, theflight controller further operates steering controls of the guidanceparachute for a rapid, controlled descent overhead the target locationuntil a predetermined minimum altitude is reached. Once thepredetermined altitude is reached, the flight controller releases theguidance parachute to transition to the landing parachute.

According to another aspect of the invention, static line droguedeployment of the parachute system is performed with a time delay onreleasing the drogue to extract and deploy the main. The time delay maybe a mechanical delay or may be controlled by the flight controller. Thetime delay allows the system to stabilize under drogue before deploymentof the main guidance wing.

According to other aspects of the invention, the release of the guidanceparachute operates to static line deploy the landing parachute.According to another aspect of the invention, a two stage harness isused to attach the parachute system to the cargo. During transport andrelease of the cargo from the airplane, the parachute system is closelyattached to the cargo. Following deployment of the drogue chute, theparachute system is spaced further away from the cargo.

According to another aspect of the invention, the parachute system ofthe invention is used with explosive cargo to create a “smart” bomb. Thegliding parachute and flight controller are used to steer the explosivecargo over a desired target location. The landing parachute may be usedto land the explosive cargo when it is over the target location.Alternatively, according to another aspect of the invention, a landingparachute is not used. The gliding parachute is used to fly theexplosive cargo at high speed into the target or the flight controllerdetonates the explosive at a preset altitude over the target.

According to another aspect of the invention, a flight controllerdetermines position of the parachute system using GPS signals andcontrols the guidance parachute to reach a desired destination.

According to another aspect of the invention, the flight controller logsposition and control information and optional sensor data during flight.The flight controller includes a microprocessor and memory. Duringflight, in order to control the parachute, the flight controllerdetermines the position and altitude of the parachute system. Thisinformation can be recorded at predetermined intervals. Information fromthe memory can be retrieved to analyze performance of the flightcontroller and the parachute system.

According to another aspect of the invention, the flight controllerincludes a transceiver, preferably a radio frequency transceiver. Duringflight, the transceiver is used to transmit position, altitude,orientation or other information to a base location. The base locationmay be located on the ground, in the deploying airplane, or otherlocation. The information from the flight controller may be used tomonitor operation of the system in real-time. Additionally, thetransceiver may receive information from the base location. Suchinformation may include manual override control of the system or changein target coordinates.

According to another aspect of the invention the steering and releaseactuators are pneumatic, being powered by compressed gas instead ofbattery power. Miniature carbon fiber high pressure compressed gas tankscan store far more power density than cold weather batteries and areunaffected by extreme cold.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a parachute system according to an embodimentof the present invention.

FIG. 2 is a top view of the parachute system of FIG. 1.

FIG. 3 is a flow diagram for operation of a parachute system accordingto an embodiment of the present invention

FIGS. 4A-G illustrate the sequence of operation of a parachute systemaccording to an embodiment of the present invention.

FIG. 5 is a top view of a flight controller according to an embodimentof the present invention.

FIG. 6 is a block diagram of the components of the flight controller.

DETAILED DESCRIPTION

In order to provide improved performance for automatic control of cargodrops, the parachute system of the present invention includes multipleparachutes and a flight controller. FIGS. 1 and 2 are respectively aside view and a top view of an embodiment of the parachute system 10 ofthe present invention when packed for deployment. The parachute systemincludes a drogue 20, a high wing loaded, guidance parachute or wing 30,and a landing parachute 40. Preferably, the guidance parachute is a highwing loaded, high speed, steerable, ram air parachute. However, anycontrollable wing or parachute may be used. Preferably, the landingparachute is a larger parachute allowing slow unguided vertical descent.A flight controller 50 is disposed below the parachutes and operates tocontrol deployment of the parachutes and steering of the guidanceparachute. The parachutes 20, 30, 40 may be of any known design basedupon the type of chute required for the specific operation.

FIG. 3 is a block diagram illustrating the operation of the parachutesystem 10 under control of the flight controller 50. Illustrationsrelating to the sequence of operation of the parachute system 10 areillustrated in FIGS. 4A-4G. As illustrated in FIG. 4A, the parachutesystem 10 is attached closely to the cargo 70 to prevent movement in thecargo hold of the plane. FIG. 4A illustrates the cargo 40 as a barrel,but any other type of cargo container, including pallets, could be used.The orientation of the parachute system and the mechanisms forattachment to the cargo will depend upon the type of cargo beingdropped.

To start the cargo drop process, illustrated in FIG. 3, the cargo andparachute system are deployed in a known manner from the deliveryaircraft at step 110. Preferably, a static line deployment is used. Upondeployment of the cargo and parachute system, the drogue 20 is deployed(step 120; FIG. 4B), preferably using a static line 21 (FIG. 1). Ofcourse, other mechanisms could be used to deploy the drogue, including acontrollable release operable from by the flight controller 50. Thedrogue properly orients the cargo with the parachute system 10 on topand releases the tie downs 25.

During the delivery flight and upon discharge of the cargo, theparachute system 10 is tightly retained against the cargo 70. However,for improved flight, the cargo 70 is preferably suspended below and awayfrom the parachute system 10 via a swivel. Thus, at step 130, the droguechute releases tie downs 25 between the parachute system 10 and thecargo 70. Preferably, the parachute system is closely attached to thecargo using 3-ring releases. Cable 24 (FIG. 4B) from the drogue bridalto the 3-ring releases allows the cargo to separate from the parachutesystem upon deployment of the drogue. Following release of the tie downs25, the cargo 70 is attached to the parachute system 10 with a harness71. The harness 71 allows the cargo to hang from the parachute system10. Any type of harness 71 can be used to retain a proper orientation ofthe cargo below the parachute system 10. Preferably, a swivel 72 isincluded in the harness 71 to allow for spurious movement of the cargofrom winds during descent. The parachute system 10 of the presentinvention is not limited to any particular tie down 25 or harness 71.Furthermore, the parachute system 10 could be directly attached to thecargo 70 with out the need for the separation in step 130.

According to an embodiment of the present invention, at step 140, aninventive hydraulic time delay is introduced for the drogue 20. Tensionon the drogue bridal is applied to a piston in hydraulic fluid. Thepiston has an orifice drilled through it to allow passage of fluid fromone side of the piston to the other. As fluid is incompressible the flowcan not go supersonic and the speed the piston can move is able to befixed. The motion of the piston is transferred to a cable that initiatesthe guidance wing deployment at the end of its stroke. The purpose ofthe time delay is to ensure the system is in stable drogue fall beforedeploying the guidance parachute 30. The delay may also be controlled bythe flight controller via an actuator (not shown). Alternatively, adouble bag system could be used for the guidance parachute instead ofthe drogue delay.

Following the drogue delay, the guidance parachute 30 is deployed (step150; FIG. 4D). As illustrated in FIG. 2, the guidance parachute isretained in a multiple flap container 31 prior to deployment. Followingthe delay, the release cable 23 is pulled which opens the bag 31.According to an embodiment of the invention, the release cable 23removes a pin from a string holding the flaps of the multiple flapcontainer 31 closed. The string also retains riser extensions 65, 66,67, 68 at the bridal 22. The riser extensions 65, 66, 67, 68 areconnected to the harness/container system 10 to carry the weight of thesystem and cargo and relieve stresses on the fabric of theharness/container system during use of the drogue. The drogue bridal 22is attached to the guidance parachute bag 30 causing it to be deployedwhen the container 31 is released. Alternatively, the release cable 23could be operated by the flight controller 50.

The guidance parachute 30 is preferably of a type having high wing loadand high speed. According to an embodiment of the invention, theguidance parachute is preferably wing loaded in the range of five totwenty (5-20) pounds per square foot wing loading, and has forwardflight speeds of forty to one hundred forty (40 to 140) miles per hour.An exception to such performance characteristics may to be when thesystem is used with extremely small payload, i.e., seventy-five (75)pounds. With small payloads, further reducing the size of the parachutebecomes impractical. Lightweight systems may fly at lower wing loadings.Current systems of the invention have been tested from four and one halfto ten (4.5-10) pounds per square foot loading.

The guidance parachute 30 is connected via four risers 61, 62, 63, 64attached to the harness/container system 10. The four risers 61, 62, 63,64 extend from the suspension harness 71, and preferably from the swivel72 to the parachute system 10. The webbing from the swivel are sewn tothe sides of the container of the parachute system. Each riser includesa 3-ring release 61 a, 62 a, 63 a, 64 a between the container system andthe guidance parachute. Before deployment of the guidance parachute, therisers 61, 62, 63, 64 extend into the multiple flap bag 31 through thecorners. Upon deployment, the risers suspend the parachute system 10 andthe cargo 70 from the guidance parachute 30.

Brake lines 81, 82 are connected to the guidance parachute 30 forcontrol. The brake lines 81, 82 are retained in sleeves 81 a, 82 aattached to the risers 61, 64, and extend into the parachute system forattachment to the steering actuators. The steering actuators areoperated by the flight controller 50 to steer the canopy 30 in a knownmanner. The steering actuators are preferably pneumatic and built as anintegrated steering module possessing multiple functions. Pneumaticallycontrolled stages can transverse linearly to pull either the left orright control line. The lines are each routed through a pneumaticguillotine cutter which allows the line connection to the actuator to besevered when transitioning from the guidance parachute to the landingparachute. Additionally, many ram air parachutes deploy best when thebrake lines are partially pulled during deployment. The force requiredto hold the brake lines during deployment is typically many times theforce required to actuate a turn once in flight. As such, so as not toover design the strength of the steering actuators, an additionalpneumatic actuator is provided to pull a pin for each line. There is aloop on each brake line that can be set or trapped by the actuationprior to retracting the pin. The pin allows a very high holding force onthe brake lines during deployment and then is retracted freeing thebrake lines to be controlled by the steering actuators.

At step 160, the flight controller adjusts the direction of the guidanceparachute 30 using the brake lines 81, 82 to direct the cargo towardsthe desired target location. Operation of the flight controller 50 forsteering the guidance parachute is discussed below.

Once the cargo 70 and parachute system 10 reaches an area approximatelyoverhead of the desired target location, the guidance parachute iscontrolled to fly in a spiral dive or holding pattern (step 170; FIG.4E). Other holding patterns, such as a figure-8 or flat spiral (slowaltitude drop maneuver), could also be used. A spiral will initiate thefastest possible vertical decent. Tested systems with a wing load offour and one half (4.5) have shown a vertical decent rate in a spiraldive of 120 mph. The cargo 70 and parachute system 10 descends withoutsignificant variation from the target location. If the flight computerdetects significant drift it will stop the spiral correct andreinitiate, if time permits once corrected. and parachute system 10reaches an area approximately overhead of the desired target location,the guidance parachute is controlled to fly in a spiral dive or holdingpattern (step 170; FIG. 4E). Other holding patterns, such as a figure-8or flat spiral (slow altitude drop maneuver), could also be used. Aspiral will initiate the fastest possible vertical decent. Testedsystems with a wing load of four and one half (4.5) have shown avertical decent rate in a spiral dive of one hundred twenty (120) mph.The cargo 70 and parachute system 10 descends without significantvariation from the target location. If the flight computer detectssignificant drift it will stop the spiral correct and reinitiate, iftime permits once corrected.

Prior to the system spiraling into the ground, at a minimum altitudepreset into the flight computer, actuators pull cables from the four3-ring releases on the guidance parachute risers to release the guidanceparachute 30. At the same time the guillotine cutters sever the brakelines to the steering actuators. A line (not shown) connects at leastone of the risers from guidance parachute 30 to a release on a multiflap container 41 containing the landing parachute. This line furtherattaches the guidance parachute 30 to the landing parachute 40 so itsdrag extracts and deploys the landing parachute. Additionally byremaining tethered, nothing is lost. The guidance parachute 30, thus,operates as a drogue for the landing parachute 40. The landingparachute, preferably a round canopy parachute, allows the cargo toslowly descend, landing unguided. The landing parachute should bereleased at a low enough altitude to prevent significant deviations fromwind drift. Risers 42 for the landing parachute are sewn on the insideof the bag to the risers 61, 62, 63, 64 on the outside of the bag. Upondeployment of the landing parachute, the parachute system maintains thesame orientation due to the consistent placement of the risers.

Militaries are content to use round parachutes from low altitudes, i.e.,one thousand (1000)-[[′]] feet. Drift from such a low altitude is easyto correct and accuracy is high. This invention simply seeks to create asystem to transport cargo from a high altitude plane out of harms way asrapidly as possible to a targeted low altitude for subsequent landingunder a conventional round cargo parachute.

FIG. 5 is a top view of components of the flight controller according toan embodiment of the present invention. FIG. 6 is a block diagram of thecomponents of the flight controller. While specific components areillustrated and discussed herein, the flight controller may be designedin any manner to provide the desired functions and operations.Preferably, the flight controller 50 includes a microprocessor 200 andassociated memory 250. The instructions for operation of themicroprocessor 200 are stored in the memory. They may be created andoperated in any known computer programming language. The microprocessor200 is programmed to provide the steps set forth in FIG. 3.

Attached to or integrated with the microprocessor 200 are other devicesto provide inputs to or outputs from the microprocessor 200 foroperation of the parachute system. In particular, the flight controller50 may include a Global Positioning Satellite (GPS) system receiver 210,a barometric altimeter sensor 220, inertial sensors 221, a decent armingswitch 222, or other sensors 225, integrated with the microprocessor 200as a single unit. Alternatively, discrete sensors may be used to provideinputs to the microprocessor 200. The microprocessor 200 usesinformation from the integrated or discrete sensors to determine theposition of the parachute system 10. The altitude is provided based on athree dimensional GPS fix using the GPS receiver 210. However, anadditional barometric pressure sensor 220 may be used for redundancy.Other sensors may include inertial navigation or gyros 221 fordetermining position in the event that GPS signals are lost or jammed.

The microprocessor 200 uses the information from the sensors todetermine position and to control the parachute system 10. Themicroprocessor 200 has outputs connected to electro pneumatic solenoids240 for controlling pneumatic actuators 230, 241, 242, 243. Thepneumatic actuators are powered by a source of compressed gas 235,preferably compressed nitrogen or dry air. Alternatively, electricmotors could be used instead of the actuators. However, the use ofpneumatic actuators with compressed gas is advantageous for theparachute system of the present invention. The extremely cold air at thehigh altitudes at which the parachute system is deployed would greatlydrain a battery or other source of electric power. By using thepneumatic actuators, the electrical requirements of the system foroperating the microprocessor 200 is very low and system weight isreduced.

The embodiment of the present invention uses two principal types ofactuators: steering control actuators 240 and guidance wing releaseactuators 230. Other actuators could be included to provide additionalfunctionality. For example, the flight controller 50 could be used todeploy the drogue or to deploy the glide parachute. If the flightcontroller performs these functions, additional actuators and solenoidswould be necessary.

The steering control actuators 241, 242, 243 operate the brake lines 81,82 of the glide parachute 30 to direct the parachute system to thetarget location. Upon deployment of the guidance parachute 30, the brakelines 81, 82 must be held in for proper inflation and stabilization. Apair of deployment actuators 242, 243 are used to hold the brake linesin. Loops in the brake lines 81, 82 are held by the deployment actuators242, 243. Once the guidance parachute is deployed and stabilized, thedeployment actuators 242, 243 release the loops and the brake lines 81,82 are positioned for normal operation. The brake lines 81, 82 arecontrolled by steering actuators 241, which may include one actuator 241a, 241 b for each line. The actuators 241 pull or release the brakelines to alter the direction of flight of the system. Upon release ofthe guidance parachute 30, the brake lines also need to be released.Actuators 236, 237 are used for this purpose. Actuators 236, 237 arepositioned around the brake lines 81, 82 at the entrance to the steeringactuators 241. Actuators 236, 237 operate guillotine cutters to cut thebrake lines 81, 82 for release. Other combinations of actuators arepossible for control of the brake lines. The steering actuators 241 maybe used to hold in the brake lines during deployment rather than thedeployment actuators. Other kinds of release mechanisms may also be usedinstead of the guillotine cutters.

Four release actuators 231, 232, 233, 234 are used to release the risers61, 62, 63, 64 holding the glide parachute 30 to the parachute system10. Each of the release actuators 231, 232, 233, 234 is connected to oneof the release cables 61 b, 62 b, 63 b, 64 b for the 3-ring releases onthe risers. When the glide parachute is to be released, themicroprocessor 200 operates the release actuators 231, 232, 233, 234 topull the release cables 61 b, 62 b, 63 b, 64 b. Alternative methods,including guillotine cutters could be used to release the risers 61, 62,63, 64 under control of the microprocessor 200.

The flight controller 50 may be powered and operated at any time duringthe deployment process depending upon when it is needed. According to anembodiment of the invention, the flight controller 50 is powered priorto deployment from the drop plane to allow a GPS fix to be obtainedbefore dropping. Software ‘arming’ of the system is possible bydetecting the vertical decent rate. However, a steeply diving airplanecan falsely arm the system and then the units would begin steering andpossible release actuators while the system is still in the cargo bay. Apreferred method uses an arming switch that senses when the guidanceparachute has left the container. This has been accomplished by use of amagnet sewn into the parachute bag and a magnetic reed switch connectedto the flight computer.

Once the guidance parachute 30 is released, the microprocessor 200operates to control the direction of flight. The GPS receiver 210provides position information which is also used to determineorientation. The microprocessor 200 provides signals to the steeringcontrol actuators 241 attached to the brake lines 81, 82 of the guidanceparachute 30 to steer the system. The target location is stored inmemory 250. The system determines the necessary changes in flightdirection to move from the currently traveled vector to one that wouldintersect overhead of the target. Preferably, the system uses PIDcontrol algorithms to prevent oversteering when correcting the flightvector. Such oversteering results in a system that flys a sinewave ordamped sinewave flight path instead of perfectly straight.

Once the target location has been reached, as determined by themicroprocessor 200, the microprocessor 200 actuates [a] steeringactuators 241 to initiate a sustained turn or spiral dive or otherholding pattern. The cargo and parachute system continues to descendover the target location. Once a set altitude is reached, as stored inthe memory 250, as determined by the altimeter 220 or the GPS receiver210, the microprocessor 200 sends a signal to the guidance wing releaseactuators 230 to release the risers 61, 62, 63, 64 of the guidanceparachute 30 and sever the brake lines, thus deploying the landingparachute. The system continues it descent using the landing parachuteuntil touchdown.

The flight controller 50 needs to be programmed with the target locationand altitude information for the landing parachute release. Input/output(I/O) ports are attached to the microprocessor 220 for the purpose ofinputting the necessary information. The I/O ports may be of any knowntype, and may include a display, keyboard, mouse, disk or other memorydrive, or a port for connection to a computer or other storage device.FIG. 6 illustrates a wireless modem 260 and antenna 261 as an I/O portfor inputting information. Additionally, if appropriate, the droguedelay time may also be entered into the system using the I/O ports.

When the glide ratio of the system is known, the flight computer may beconnected to an indicator light to show when the drop plane is withinthe cone of acceptability to drop the cargo and have it fly to itsintended target. This aids drop personnel in the cargo plane.

Since the microprocessor 200 of the flight controller 50 is receivinginformation about the flight, such as position and altitude, theinformation can be stored in the memory 250. A timer (not shown) can beused to provide time based information in the memory 250. Uponcompletion of the drop, the stored information from the memory 250 canbe retrieved through the I/O ports for analysis and review. Othersensors could also be included in the flight controller 50 fordetermining and recording data for analysis. For example, sensors couldbe used to determine G-forces, stress and strain placed on variouscomponents of the parachute and the cargo. These sensors can beconnected to the microprocessor 200 to store the sensed information inthe memory.

The flight controller 50 may also include a transceiver for wirelesscommunication with the flight controller. The wireless modem 260 andantenna 261 illustrated in FIG. 6 can also function as a transceiver.The transceiver is preferably RF, but can include an infrared or othertransmission medium. The transceiver can be used to output position,altitude or other information, in real time to a base station. The basestation may be in the delivery aircraft, at the target location, or someother control position. The information transferred from the flightcontroller 50 to the base station can be used to monitor flight andoperation of the system. Additionally, the transceiver can be used toreceive information from the base station. The base station couldtransfer information changing any of the flight parameters, such as thetarget location. Alternatively, direction information could betransmitted to the flight controller for the steering controller 240.Thus, the parachute system could be remote controlled by an operator atthe base station, instead of automatic operation. In a preferredembodiment telemetry data sent to the base station is graphicallydisplayed on a screen to allow remote control without visual contactwith the parachute system.

A GPS repeater provides the GPS signals within the cargo area of theaircraft. Thus, the GPS receiver of the flight controller can acquire aposition lock prior to being dropped. The flight controller must bepowered on several minutes before drop to allow a valid ephemeris to bedownloaded which can take up to four (4) minutes. If they are then shutoff, the software directs them to look for GPS satellites as if theywere in the same position from time of power off. With the inventivesystem, it has been found that up to two (2) hours ‘black out’ periodresults in a reacquisition of position lock in forty (40) ms to eight(8) sec, after two (2) hours extending out to four (4) hours the timelengthens to its maximum of up to four (4) minutes.

FIG. 3 illustrates the steps for operation of the flight controllerafter launch of cargo and parachute system from the delivery aircraft.The flight controller would also include a program for operation in apre-launch mode to prepare for launch. The pre-launch mode include thesteps of uploading target coordinates through the I/O ports anddownloading a valid ephemeris for the drop location to the GPS receiver.Target coordinates on the inventive system may be uploaded by an RS232or other connection from a laptop or dedicated handheld terminal, orsimply by inserting a memory chip with the data into the flightcomputer, i.e. a compact flash card is uploaded with target data fromthe laptop software and then inserted into the flight computer. Theephemeris is automatically acquired by the GPS.

In another embodiment, the parachute system of the present invention isused to convert dumb bomb to guided ‘smart’ bombs. Militaries have beenconverting inexpensive ‘dumb’ bombs into more effective guided weaponsby a bolt on tail kit that includes a guidance computer/sensors/softwareand actuators for piloting the tail fins of the bomb, i.e.,JDAM/conversion. These devices have received extensive use in the GulfWar and in Afghanistan. Cost wise they are very desirable, butperformance wise they have certain shortcomings. The bombs typicallyweigh from five hundred to two thousand (500-2000) pounds. The tail finsare an extremely small wing surface for guiding such a heavy weight; assuch, they are not capable of much course correction or significantglides. They suffer from accuracy and standoff shortcomings. A parachutesystem of the present invention attached to a dumb bomb, typically atthe tail, to create a bomb guided by a high performance guidanceparachute overcomes the problems of limited standoff and accuracy whileremaining economically competitive. The coordinates of the desiredtarget are loaded into the system. Since the bomb is intended to explodeat impact, the landing parachute can be eliminated. Soft landingrequired for cargo is not required for bombs. Thus, step 180 in FIG. 3can be eliminated allowing the system to fly under the high speed, highwing load guidance wing until impact with the target or triggered todetonate at a predetermined distance above the target.

While the present inventions have been described with a certain degreeof particularity, it is obvious from the foregoing detailed descriptionthat one skilled in the art may make one or more modifications which aresuggested by the above descriptions of the novel embodiments.

1-27. (canceled)
 28. A bomb delivery system comprising: a guidanceparachute attached to the bomb; and a flight controller attached to theguidance parachute for steering the guidance parachute to apredetermined target location.
 29. The bomb delivery system according toclaim 28, wherein the flight controller includes: means for releasingthe bomb when the system reaches the target location when below a presetaltitude.
 30. The bomb delivery system according to claim 28, whereinthe guidance parachute is wing loaded over three pounds per square foot.31. A bomb delivery system comprising: a steering ram air guidanceparachute, connectable to said bomb for a first period of time followinglaunch adapted to quickly move said bomb after drop to a first altitudesubstantially overhead a target location; and a flight controllerresponsive to said target location and to said first altitude, forsteering said steering ram air guidance parachute to the first altitudethat is a predetermined first distance substantially overhead saidtarget location.
 32. The bomb delivery system according to claim 31,further comprising a drogue connectable to said bomb for a second periodof time prior to the first period of time.
 33. The bomb delivery systemaccording to claim 32, further comprising a drogue delay timerdetermining said second period of time.
 34. The bomb delivery systemaccording to claim 31, wherein the flight controller includes: a GPSreceiver providing information about a current location of the bomb; aprocessor for determining the system's flight vector and desired flightpath capable of controlling actuators to steer the guidance parachute.35. The bomb delivery system according to claim 34, wherein the GPSreceiver is loaded with an ephemeris of the target location.
 36. Thebomb delivery system according to claim 34, wherein the actuators arepneumatically powered.
 37. The bomb delivery system according to claim31, wherein the guidance parachute is loaded over three pounds persquare foot.
 38. The bomb delivery system according to claim 31, whereinthe altitude dropping maneuver includes a spiral dive.
 39. The bombdelivery system according to claim 31, wherein the flight controllerincludes an altimeter for determining an altitude of said bomb.
 40. Thebomb delivery system according to claim 31, wherein the flightcontroller includes a transmitter for sending data from the flightcontroller to a base station.
 41. The bomb delivery system according toclaim 31, wherein the flight controller includes a transceiver fortransmitting data between the flight controller to a base station. 42.The bomb delivery system according to claim 31, wherein the flightcontroller stores data relating to operation of the flight controllerduring flight.
 43. A method for air dropping a bomb secured to aparachute system comprising the steps of: launching said bomb from adelivery aircraft; deploying a guidance parachute; and controlling saidguidance parachute to position said bomb to a first altitudesubstantially overhead of a target location.
 44. The method as claimedin claim 43, further comprising the step of stabilizing said bomb undera drogue after launching said bomb and prior to deploying said guidanceparachute.
 45. The method as claimed in claim 44, further comprising thestep of using a hydraulic timing mechanism to control the drogue falltime.
 46. The method as claimed in claim 44, wherein the step ofstabilizing the bomb occurs for a predetermined period of time.
 47. Themethod as claimed in claim 43, further comprising the step of releasingtie downs holding said parachute system to said bomb to suspend saidbomb from the parachute system.
 48. The method as claimed in claim 47,wherein the step of releasing the tie downs includes releasing the tiedowns with tension from a bridal on the drogue.
 49. The method asclaimed in claim 43, wherein the step of steering the guidance parachuteincludes the steps of: determining a current location of said bomb;determining a direction from the current location of said bomb to thetarget location; and controlling the guidance parachute for flight inthe determined direction.
 50. The method as claimed in claim 49, whereinthe step of determining a current location of said bomb includesobtaining a position location from a GPS receiver.
 51. The method asclaimed in claim 50, further comprising the step of loading an ephemerisfor the target location in the GPS receiver prior to the launching step.52. The method as claimed in claim 43, further comprising the steps of:determining flight data relating to flight of said parachute system andsaid bomb; and storing said flight data.
 53. The method as claimed inclaim 43, further comprising the steps of: determining flight datarelating to flight of said parachute system and said bomb; andtransmitting said flight data to a base station.
 54. The method asclaimed in claim 43, further comprising the step of transmitting controlinformation to the parachute system for controlling the guidanceparachute.